Aminophenylamidines, their production and their medicinal use

ABSTRACT

The present invention relates to new aminophenylamidines and cycloamidines and salts thereof, to processes for their production, and to their use as medicines, especially as parasiticides. Acylaminophenylformamidines, such as N-(p-acetamidophenyl)-N&#39;&#39;, N&#39;&#39;-dimethylformamidine (U.S. Pat. No. 3,184,482) are already known. This compound, as well as other formamidine derivatives, are, however, ineffective against helminths. Furthermore, Nphenylacetamidines, such as N-(p-chlorophenyl)-N&#39;&#39;,N&#39;&#39;dimethylacetamidine, are known. These compounds are also ineffective against helminths.

United States Patent Wollweber et al.

AMINOPHENYLAMIDINES, THEIR PRODUCTION AND THEIR MEDICINAL USE Inventors: I-Iartmund Wollweber, Wuppertal,

Germany; Winfried Flucke, Beenleigh, Australia Assignee: Bayer Aktiengesellschaft, Germany Notice: The portion of the term of this patent subsequent to Dec. 17, 1991, has been disclaimed.

Filed: Sept. 24, 1973 Appl. No.: 399,813

Related U.S. Application Data Division of Ser. No. 151,575, June 9, 1971, Patv No. 3,855,292.

Foreign Application Priority Data June 13, 1970 Germany 2029299 U.S. Cl 260/564 RF; 260/501.14 Int. Cl. C07C 123/00 Field of Search 260/564 RF, 501.14, 465 E [5 6] References Cited OTHER PUBLICATIONS Larizza et al., J. Org. Chem. Vol. 29 pp. 3697-3700 (1964).

Primary ExaminerGerald A. Schwartz 5? ABSTRACT The present invention relates to new aminophenylamidines and cycloamidines and salts thereof, to processes for their production, and to their use as medicines, especially as parasiticides.

Acylaminophenylformamidines, such as N-(p-acetamidophenyl)-N,N-dimethylformamidine (U.S. Pat. No. 3,184,482) are already known. This compound, as well as other formamidine derivatives, are, however, ineffective against helminths. Furthermore, N-phenylacetamidines, such as N-(p-chlorophenyl)-N',N-dimethylacetamidine, are known. These compounds are also ineffective against helminths.

4 Claims, N0 Drawings R is a hydrogen atom or an alkyl or alkylene group AMINOPIIENYLAMIDINES, THEIR PRODUCTION containing up to three carbon atoms;

AND THEIR MEDICINAL USE R is a hydrogen, chlorine or bromine atom or a This is a division of application Ser. No. 151,575 filed methyl or cyano group; June 9, l97l U.S. Pat. No. 3,855,292. R is a hydrogen, chlorine or bromine atom or an This invention provides aminophenylamidines and alkyl group with up to three carbon atoms or a meaminophenylcycloamidines of the general formula: thoxy, trifluoromethyl or cyano group;

'2 1 R 5 R R N N=C-N (1) H 4 6 in which: R is methyl or ethyl group; and either R is a hydrogen atom or a straightor branched- R is a methyl or ethyl group or a cycloalkyl group chain alkyl, alkoxy alkyl or alkenyl group; with 3 t0 6 Car on at ms; and R and R are the same or different and are each ahy- R is an alkyl or alkoxy group-with l to 3 carbon drogen, fluorine, chlorine or bromine atom or a atoms; straightor branched-chain alkyl, alkenyl, or alk- R and R together are a +C fim group, m being a OXy group or a cyano or trifluoromethyl grou whole number from 3 to 5; and their salts. R is a straightor branched-chain alkyl or alkenyl The invention further provides four processes desiggroup or a cycloalkyl group; and either nated as a, b, c and d for the production of the new R is a straightor branched-chain alkyl, lk n l Qr aminophenylamidines and -cycloamidines and their alkoxy group; and salts. R is a hydrogen atom or a straightor bra h d- Process (a) comprises reacting an aniline derivative chain alkyl, alkenyl, alkynyl or alkoxy group; or 0f the general formula R and R together with the amino nitrogen atom and the amidino carbon atom form a five, six or seven- 3 membered ring; and their salts. R These aminophenylamidines and -cycloamidines and their non-toxic salts are useful for combating parasites, N N l 2 especially helminths, in human and veterinary medicine. H 4

Alkyl and alkoxy groups R preferably contain 1 to 5, especially 1 or 2, carbon atoms, and the alkenyl group R f bl nt ins 2 to 5 carbon t with a carboxylic acid amide or thioamide of the gen- Alkyl groups R preferably contain 1 to 5, most preferal formula; erably l or 2, carbon atoms, and alkenyl groups R generally contain 2 to 5, preferably 2 or 3, carbon atoms. R

Alkyl and alkoxy groups R and R preferably contain 1 to 6, especially 1 to 3, carbon atoms, and alkenyl groups R and R preferably contain 2 to 6, especially 2 W G N 3 l to 4, carbon atoms.

Alkyl and alkoxy groups R preferably contain 1 to 4, 6 especially l to 3, carbon atoms. The alkenyl and alky- R nyl groups R preferably contain 2 to 4 carbon atoms.

If R and R together with the amine nitrogen atom or with a salt or a reactive derivative thereof. In general form a S-membered to 7-membered ring, R and R toformulae 2 and 3 W is an oxygen or sulphur atom and gether preferably represent the group -(CH,),,--, in R, R and R to R are as defined above.

which n represents 3, 4 or 5. The reaction is optionally carried out in the presence The alkyl groups R preferably contain 1 to 5, espeof a condensation agent. The reaction product can be cially l to 3, carbon atoms, and the alkenyl groups R isolated in the form of one or its salts or in the form of preferably contain 2 to 5, especially 2 or 3, carbon a free base, and then optionally converted into any atoms. The cycloalkyl group R preferably possesses 3 other desired salt.

to 7 carbon atoms. As salts of the carboxylic acid amides 3 there are to The active substances according to the invention are be understood both salts with organic acids, (for exambasic in character. They can be used as free bases or in ple, the acetates) and salts with inorganic acids (for exthe form of their salts, for example hydrohalides, such ample the hydrohalides or sulphates).

as, for example, hydrochlorides, sulphates, phosphates, By reactive derivatives of the amides 3 there are, for nitrates, acetates, naphthalene disulphonates or pamoexample, to be understood derivatives which are obates, the Salts i hyl n i -(2-hydroxynaphtained by reaction of an amide or thioamide of the genthoic acid-3). The preferred salts are the hydr0chloeral formula 3 with an inorganic acid (for example, hyrid s drochloric acid, boron trichloride or sulphuric acid) or Particularly preferred compounds are those of the with an inorganic or organic acid halide (for example, general formula in Whichl phosphorus oxychloride, phosphorus pentachloride,

phosgene, thionyl chloride, benzoyl bromide, ptoluenesulphonyl chloride or a mixture of phosgene/aluminium chloride, or phosgene/hydrogen chloride or phosgene, phosphorus oxychloride) or with a trialkyloxonium fluorborate (1 carbon atoms per alkyl group) or with a dialkyl sulphate (1 5 carbon atoms per alkyl group) or an alkyl halide (1 5 carbon atoms).

As condensation agents that can be employed in process a, there may for example be mentioned:

Inorganic acids (for example, hydrochloric acid, boron trichloride, sulphuric acid) or inorganic or organic acid halides (for example phosphorus oxychloride, phosphorus pentachloride, phosgene, thionyl chloride, benzoyl bromide, p-toluenesulphonyl chloride or a mixture of phosgene/aluminium chloride, or phosgene/hydrogen chloride or phosgene/phosphorus oxychloride) or trialkyloxonium fluorborates (1 to 5 carbon atoms per alkyl group) or dialkyl sulphates (1 to 5 carbon atoms per alkyl group) or alkyl halides (1 to 5 carbon atoms).

When a thioamide is used, i.e. W sulphur in general formula 3, a desulphurizing agent, for example, I-IgO, Ag O or I-Ig(CN can be used advantageously in addition to one of the abovementioned condensation agents, or without one of these condensation agents.

The reaction components 2 and 3 are preferably employed in the stoichiometrically required amounts.

The reaction can'be carried out in any inert organic solvent; among such solvents, aromatic, optionally halogenated, hydrocarbons, for example, benzene, toluene or dichlorobenzene, optionally chlorinated aliphatic hydrocarbons, for example methylene chloride and chloroform; tetramethylene-sulphone, and lower aliphatic alcohols, for example, methanol and ethanol, should be mentioned.

The reactants are preferably brought together at room temperature (about 20C) and, if appropriate, are warmed to between 30 and 150C, preferably 80 to 120C, in order to complete the reaction.

The success of the reaction does not depend on the sequence in which the reactants are brought together. The new compounds are isolated in the customary manner.

Process b comprises reducing a nitrophenylamidine or -cycloamidine of the general formula:

or a salt thereof, to obtain an aminophenylamidine or -cycloamidine, of the general formula:

formula ii. alkylated reductively with an oxo compound of the general formula:

to obtain a Schiff base which is reduced to give the required aminophenylamidine, -cycloamidine or salt.

In the above general formulae 4, 6 and 7, R, R, R to R are as defined above, B is a reactive ester group or a halogen atom; R is a straight-chain or branched alkyl or alkenyl group; R is a hydrogen atom or an alkyl group: and R is an alkyl group.

Straight-chain or branched alkyl groups R preferably contain 1 to 5 carbon atoms, especially 1 or 2 carbon atoms.

Halogen atoms B are preferably chlorine or bromine atoms. Reactive ester groups B are, for example, arylsulphonyloxy, for example, benzenesulphonyloxy or toxyloxy, or alkylsulphonyloxy, for example methanesulphonyloxy, or alkoxysulphonyloxy (preferably with 1 or 2 carbon atoms in the alkyl or alkoxy group).

The alkyl groups R preferably contain 1 to 5, especially l to 4, carbon atoms and the alkyl groups R preferably contain 1 to 5, especially 1 or 2, carbon atoms.

The nitrophenylamidines of general formula 4 and their salts can be reduced by any suitable method.

The reduction can advantageously be effected catalytically, for example with Raney nickel as the catalyst, optionally in the presence of a solvent, such as an alcohol, for example methanol or ethanol, a solution of hydrochloric acid in ethanol, or an ether for example tetrahydrofuran, at a temperature of 0 to 100C, preferably of 20 to C, optionally under pressure, for example at l to 100, preferably 60 to 80, atmosphere gauge.

The reduction can also be carried out with zinc/hydrochloric acid and stannous chloride, preferably in an aqueous medium (water).

Furthermore, the reduction can be carried out with sodium sulphide, for example in an alcohol, for example, methanol and ethanol, or in an ether, for example, in tetrahydrofuran, at temppratures of 20 to C, preferably at the boiling point of the solvent.

Further reducing agents which can be used are complex metal hydrides, such as, for example, sodium boranate in alcohol (preferably ethanol)/water, at temperatures of, preferably, 20 to 80C.

In process b (i) 1 to 2 mols of the alkylating agent of general formula 6 are preferably employed per mol of the intermediate compound 5.

Examples of suitable solvents for use in step i are water, alcohols, for example, methanol or ethanol, ketones, for example, acetone, ethers, for example, tetrahydrofuran, aromatic hydrocarbons, for example, benzene or toluene, or mixtures of these solvents. An increase in the yields can be achieved by the addition of auxiliary bases such as, for example, sodium hydroxide, sodium and potassium carbonate, pyridine or triethylamine.

The reaction is carried out at 0 100C, preferably at to 40C.

In process b (ii) the reactants 5 and 7 are preferably employed in approximately molar amounts. Solvents which can be used for this reaction, which is carried out at 0 to 100C. preferably at about to 60C, are, for example, alcohols for example, methanol or ethanol, ethers, for example, tetrahydrofuran, and aromatic hydrocarbons for example, benzene or toluene. The Schiffs base obtained in this manner is hydrogenated, optionally being isolated, by any suitable method. For instance, the base maybe catalytically hydrogenated, for example with Raney nickel as the catalyst. The catalytic reduction is preferably carried out at room temperature (about 20C), and optionally under pressure (1 to 80 atmospheres gauge, preferably 60 atmospheres gauge). As a solvent an alcohol, for example methanol and ethanol, an aromatic hydrocarbon, for example, benzene and toluene, or an ether, for example, tetrahydrofuran can be used.

The reduction of the Schiffs base can also be effected by means of a complex metal hydride (approximately stoichiometrically required amounts), for example, sodium borohydride. In this case the reaction is carried out at temperatures of 20 to 80C. Here, alcohols, for example methanol and ethanol, optionally in admixture with water, are preferably used as solvents.

Process c comprises reacting an aminophenylamidine or -cycloamidine of the general formula:

N=C-N (5) i.e. a compound of the general formula 1 in which R is hydrogen, with an aliphatic or aromatic aldehyde to obtain a Schiff base quaternising the Schiff base with an alkylating agent of the general formula: ti B-R (6) and subsequently hydrolytically splitting off the aldehyde portion of the product. If a salt is required this is then produced in any suitable manner.

In general formulae 5 and 6, R,R to R and B are as defined above.

In process c, the compound of the general formula 5 is reacted with any suitable aldehyde for example, acetaldehyde or benzaldehyde, according to any suitable method, to give the Schiff base. The reactants are preferably employed in molar amounts. The reaction temperatures are preferably between 0 and 80C, preferably between 20 and 40C. Any inert organic solvent may be used, for instance, an alcohol, for example methanol and ethanol, an aromatic hydrocarbon, for example benzene and toluene, or an ether, for example, tetrahydrofuran.

The Schiff base is quaternised, optionally after being isolated, by means of the alkylating agent (6) by any suitable method, preferably at temperatures between 20 to 100C, especially between to C. Any inert organic solvent, for example benzene, toluene and tetrahydrofuran can be employed. The subsequent hydrolysis is preferably carried out without isolation of the quaternised Schiff base, perferably at temperatures between 20 to 100C, especially between 40 and C, and preferably in an aqueous alcohol, especially ethanol.

Process d comprises hydrolytic splitting of an acylaminophenylamidine or -cycloamidine of the general formula:

in which R, R and R to R are as defined above and R? is an acyl or acyloxy group, preferably with l 5 carbon atoms.

The hydrolytic splitting is carried out by any suitable method; many such methods are known in the art.

The hydrolysis is preferably carried out in the presence of a strong acid, such as hydrochloric acid or sulphuric acid. Water, or a mixture of water with an alcohol, is used as a solvent. The hydrolysis is preferably carried out at the boiling point of the solvent.

The following Examples illustrate the process according to the invention for the production of the new aminophenylamidines and cycloamidines.

All temperatures are given in degrees centigrade (C).

All starting compounds are known or are obtainable by known processes.

|3H /c1i N C N 620 g (3-mols) of N-(4-nitrophenyl)-N,N'-dimethylacetamidine in 1250 ml of ethanolic hydrochloric acid (3.3 mols) are hydrogenated with the aid of Raney nickel as the catalyst, at 70 80 and 80 to atmospheres gauge hydrogen pressure. The mixture is evaporated in vacuo, the residue is taken up in water and rendered alkaline with sodium hydroxide solution, the base which separates out is extracted with ether, the extract is evaporated, and the residue is distilled in vacuo; the product is N-(4-aminophenyl)-N',N'-dimethylacetamidine, boiling point M 158 melting point 93 95 (from ethyl acetate); yield 426.5 g, monohydrochloride, melting point 273 274.

The following compounds are obtained by analogous processes:

VII

7 8 H N R' R" R" R RV" Boiling EXAMPLE 3:

' point/mm Hg H C 4-:H H 2-Cl CH3 CH CH, 172/0.3 I 3 5 4 H H 3Cl CH CH CH 170/0.3 4-NH: 2-Cl 6-Cl CH: CH: CH: 19o/0.5 5 (313m C N 4-NH H 2-CH CH CH CH 17S/0.6 4 NH H 2-0CH CH CH CH l80/0.4 CH 4-NH H z-cF CH, CH CH, l73/0.3 3 4-NH H 2-CN CH, CH CH 168/0.2 4--NH 2-CN 6--CN CH CH CH 184/0.3 23 g of lsobutyraldehyde are added dropwise, at 20, 2::3: ;:g gga $33 5:: 238: to 53 g (0.3 mol) of N-(4-aminophenyl)-N',N'-dime- 4-NH: H H 3 1 CH: c i 7 1 thylacetamidine, dissolved in 500 ml of benzene, the j-gh g 3 $33 g g- 1 13/8 mixture is heated for 7 hours whilst connected to a H H Z 17, 4 water separator and the N-t l-isobutylideneaminog-NH H H C,H C,H CH l80/0.3 phenyl)-N',N-d1methylacetam1d1ne is distilled in N H H H CH CH 154/0.2 0 o H H H czjs 600/02 vacuo, boiling point M 156 160 8.3 g (0.066 mol) 4-NH H H H C H, CH l68/0.2 of dimethyl sulphate are added to 13 g (0.056 mol) of 4-NH H H H H CH3 hi om u d lv 'n 0 4 NHz H H CH3 OCHa CH3 1630/02 t s c po nd,disso ed 1 15 ml of benzene, the 4 NH2 H H CH3 OCzHs CHa 1680/02 mixture 1s heate for one hour under reflux, the ben- H zene is decanted off, the residue is taken up in ml of 2 50% strength ethanol, and the mixture is heated for one 0 hour under reflux. After evaporation in vacuo, and

treatment of the residue with sodium hydroxide solution, the free base is extracted with ether and distilled: EXAMPLE 2 o o boiling point M hydrochloride, melting The following compounds are produced in accorpoint 226228. dance with the method described in Example 1, by re- 25 The following compounds are produced by analoduction of 2-(nitro-phenylimino)-azacycloalkanes: gous processes:

III

/(CH H N N C III R VII R N N C N (13) V g/ R I n H,N R R R" Boiling point/ mm Hg 3 4 NH H H CH /0.1 Melting point 85-86 3 4NH2 2-Cl H CH; Melting point 9l92 3 4--NH 2-CH H CH, /0.1 3 4-NH 2Br H CH 205/0.1 3 4-NH1 3-Cl H CH3 l93/0.2 3 4 NH 3--CH H CH 192/0.1 3 4--NH 2-Cl 6-Cl CH3 210/0.2 3 4-NH, 2CN H CH, l8l/0.2 3 4-NH, H H CZHB l74/O.2 3 4--NH, 2Cl H CZHI, l88/0.l 4 4--NH2 H H CH3 l78/0.1 4 4-NH, 2-Cl H CH 196/0.1 s 4NH 2-Cl H CH: 203/0.l 5 4-NH, H H CH3 l93/0.l 3 4- NH, H H H l78/0.2 3 4-NH, 2-CF;, H CH Melting point l82/0.2

cH -\m U 1 l VI R"RN R' R R" R" R"" Boiling point/ mm Hg 4 H,C HN 2-Cl H CH CH cH 170/0.5 4-H;,C-HN 2-Br H CH, CH CH 178/0.5 4 H,C,-HN 2-c| H CH, CH CH 172/0.2 4 H,c,-HN H H CH, CH CH l63/0.5 4--H,C3HN H H CH3 CH3 CH5 l7l/O.6 4(CH ),HCHN H H CH CH, (:H l69/0.6 4-H C Hc=Hc cH,HHN H CH3 CH, cH l78/0.4 4-H C-HN H H CH ocH cH l62/0.4 4-H CHN 2 c1 H CH, OCH CH i78/O.6 4 cH,0 cH, H CH CH CH |s0/0.2

cH, HN

EXAMPLE 4:

CH 3 CH CHCH -H.N N=C-N (14) CH H 35 g of the N -(fl-isobutylideneaminophenyl)-N',N- h u! RIV w :85:35 Hg dimethylacetamidmeobtained accordingto Example 3, 3 4 CH NH 2 Cl H CH [ma/02 dissolved in 250 ml of tetrahydrofuran, are hydgoge- 3 Q H o :2 nated with Raney nickel as the catalyst, at 20-50 and 3 4-c,H,-NH H H CH 18310.3 3 4CH NH H H CH 186 0.2 60 atmospheres gauge of hydrogen. After filtering off 3 H Z the catalyst, and distilling, 17.5 g of N-(4- 4 4-CH3NH H H CH l83/0.3 I 4 4 -CH NH 2-Cl H cH 202/0.2 isobutylaminophenyl) N ,EI dlmethylacetamidme, 5 H 212,70. boiling point m 138 -145 are obtained. 5 NH H H cH, l96/0.2

EXAMPLE 5: EXAMPLE 6:

CH I 5 3 H N -N (9) 25 g of N-(4-carbethoxyaminophenyl)-N,N'-dimethylacetamidine in 100 ml of concentrated hydrochloric acid are heated for 2 hours under reflux. After evaporation, the residue is taken up in water and rendered alkaline with sodium hydroxide solution, and the aqueous phase is extracted with a mixture of ether and chloroform. After distillation, 12 g of N-(4-aminophenyl)- N,N'-dimethylacetamidine, boiling point l58-165, melting point 9395, are obtained.

The fact that the new aminophenylamidines and cycloamidines and their salts show a strong and wideranging anthelmintic activity is surprising and unforeseeable.

The new compounds are substantially more effective than other known anthelminitics of the same general action, such as, for example, bephenium hydroxynaph- 1 l thoates, l,4-phenylene-diisothiocyanate, perchloroethylene, thiabendazole an'd parbendazole.

Special attention is drawn to the fact that excellent results are achieved with a single administration of the new compounds.

The provision by the invention of these new compounds constitutes a substantial extension of the available range of anthelmintics.

In particular, the compounds manufactured according to the invention for example display a surprisingly good and broad action against the following helminths (nematodes and cestodes):

l. Nematodes 7. Heterakis spumosa from the family of the Hezerakidae;

ll. Cestodes.

l. Hymenolepis nana and Hymenolepis microstoma (tapeworms) from the super-family of the Taenioidea.

The action of the new compounds was tested in animal experiments, after oral and parenteral administration to test animals severely infected with parasites. The dosages used were tolerated very well by the test animals.

The unexpected superiority of the compounds according to the invention, as well as their excellent action, is shown by the examples of Tests A D (Tables 1 to 4).

EXAMPLE A Hookworm Test/Dogs Dogs experimentally infected with Ancylostoma caninum were treated after the end of the pre-patent period of the parasites.

The amount of active compound was administered orally, as the pure active compound or dissolved in 10% strength lactic acid, in gelatine capsules.

The degree of action was determined by counting the worms expelled after treatment and the worms remaining in the test animal after dissection, and calculating the percentage of worms expelled.

The active compounds tested, the dosages used, and the action are summarised in the table which follows.

Table l Hookworm Test/Dogs Active compounds Dose Action mg/kg in% known compounds for comparison:

H CO-NH- NmCH N\ .H I (I7) CH CH 1 3 cl- -N=C-N (18) 0 ClC=CCl I (l9) 300 82 Cl Cl S=C=N-N=C=S Sl a l;-o.- c|1 M04 CH Q Table l-continued Hookworm Test/Dogs Active compounds Dose Action mg/kg in N NH-C 200 93 CH O 3 Dose Action Active compounds according to the invention mg/kg in 3 5 99 H N -N=C -N (9) 2.5 99 1 e9 04 /01 10 94 t 5 76 H N N=C-N .HC] (24) 25 72 ci-l 1 17 C] CH H NQ-Ni 25 CH 1 CH NH N=C-N .HCl (27) 25 3 I /CH N N==C-N .HCi (28) i0 99 Literature: Rawes, DA. (I961): The activity of Bephenium Hydrocynaphthoate against Hookworms in the Dog VeLRec. 73 (16), 390-392 Literature: Theodorides. VJ. and Mv Laderman 1968): Parbendazolc in the Treatment of Intestinal Nematodes of Dogs and Monkeys. Vet.Med. 63 (I0).

EXAMPLE B orally as pure active compound, in gelatine capsules.

The degree of dilution is determined by counting the worms expelled after the treatment and the worms re- Sheep experimentally infected with Bunostomum 5 maining in the test animals, after dissection, and calcutrigonocephalum were treated after the end of the prelating the percentage of worms expelled.

patent period of the parasites. The active compounds tested, the dosages used and The amount of active compound was administered the action are shown in the table which follows.

Hookworm Test/Sheep Active Compound Dose Action mg/kg in% orally, as pure active compound, in gelatine capsules. EXAMPLE D The degree of action was determined by counting the coilworm Test/Dog l l elipelled after treatmen? and the worms Dogs naturally infected with Toxocara canis or Texasi i m the test ammals after dlssecuon and calm" 3 caris leonina were treated orally. The amount of active ating the percentage of worms expelledcompound was administered orally, as pure active com- The active compounds tested, the dosages used and und or as a 10% strength solution in lactic acid, in the action are shown in the table which follows. gelatine capsules Table 2 Hookworm Test/Sheep Active compounds Dose Action mg/kg in CH 1 l 3/043 Base 2.5 95 H N N C-N 9) Base i0 100 2 Hydrochloride s 100 3 C H 3 2 NIC-N (29) 10 97 83 H2N N N (26) 23 EXAMPLE c The degree of action is determined by counting the Test Worm of Large Intestine/Sheep 5 worms expelled after the treatment and the worms re- Sheep naturally infected with Chabertia ovina were maining in the test animals, after dissection, and calcutreated after the end of the pre-patent period of the lating the percentage of worms expelled.

parasites. The active compounds tested, dosages used and ac- The amount of active compound was administered tion are summarised in the table which follows.

TABLE 4;

Coilworm Test/Dog Active Compounds Parasite Dose Action mglkg in% CH CH Toxocara 2.5 I 3/ 3 I H N :C-N HC] Toxascaris 5.0 96

I Toxocara 10.0 60 :C- .HCl 2" Toxascans 10.0 80

CH Cl In general it has proved advantageous to administer amounts of 0.1 to 50 mg of the new compounds per kg of body weight per day in order to achieve effective results.

Nevertheless it may at times be necessary to deviate from the amounts mentioned, and in particular to do so as a function of the body weight of the test animal or of the nature of the method of administration, but also because of the variety of animal and its individual behaviour towards the medicament or because of the nature of the formulation of the latter and the point in time, or interval, at which it is administered. Thus, it may in some cases suffice to use less than the abovementioned minimum amount, whilst in other cases the upper limit mentioned must be exceeded. Where major amounts are administered, it may be advisable to divide these into several individual administrations over the course of a day. The same dosage range is envisaged for administration in human medicine and in veterinary medicine. The general sense of the other comments made above also applies.

As stated above, this invention also relates to the pharmaceutical use of the new aminophenylamidines and -cycloamidines and their non-toxic salts.

Accordingly, the present invention provides a pharmaceutical composition containing as an active ingredient at least one of the new aminophenylamidines and -cycloamidines of the general formula 1 given above, or a non-toxic salt thereof, in admixture with a pharmaceutically acceptable solid or liquid diluent or carrier as hereinafter defined.

in the present specification the expression pharmaceutically acceptable diluent or carrier" means a nontoxic substance that when mixed with the active ingredient or ingredients renders it suitable for administration. The expression preferably excludes water and low-molecular weight organic solvents commonly used in chemical synthesis, except in the presence of other pharmaceutically necessary ingredients such as salts in correct quantities to render the composition isotonic, buffers, surfactants, colouring and flavouring agents, and preservatives. Examples of suitable liquid and solid diluents and carriers are the following:

Buffered aqueous solutions; isotonic saline aqueous solutions; non-toxic organic solvents; such as paraffins, (for example petroleum fractions); vegetable oils (for example groundnut and sesame oils); alcohols, (for example ethyl alcohol or glycerol); glycols (for example 18 propylene glycol or polyethylene glycol); solid excipients, for example, natural ground rock (for example kaolins, aluminas, talc or chalk), synthetic rock powders (for example highly disperse silica or silicates); and sugars (for example unrefined sugar, lactose and glucose). Examples of pharmaceutical compositions according to the invention are ointments, pastes,

creams, sprays, lotions, aqueous suspensions, emulsions and solutions, elixirs, syrups, granules and powders, either free-flowing or compressed into tablets.

The compounds and pharmaceutically acceptable salts of the present invention may be administered perorally.

One group of preferred pharmaceutical compositions of the invention are therefore those adapted for oral administration. The diluents and carriers used are preferably therefore those that adapt the active ingredient or ingredients for oral administration. Examples of such diluents and carriers are solid vehicles, excipients and lubricants such as glucose, lactose and sucrose, corn and potato starch, sodium carboxymethyl cellulose, ethyl cellulose and cellulose acetate, powdered gum tragacanth, gelatin, alginic acid, agar, stearic acid, sodium, calcium and magnesium stearates, sodium lauryl sulphate, sodium citrate, calcium carbonate, and dicalcium phosphate.

The pharmaceutical compositions of the invention may also contain other non-toxic adjuvants and modifiers such as dyes, surfactants, for example, emulsifiers, such as non-ionic and anionic emulsifiers (for example polyoxyethylene-fatty acid esters, polyoxyethylenefatty alcohol ethers, alkylsulphonates and arylsulphonates), and dispersing agents (for example lignin, sulphite waste lyes, methylcellulose, starch and polyvinyl pyrrolidone), perfumes, flavouring agents, preservatives and biocides.

The compounds and pharmaceutically acceptable salts of the invention may also be administered parenterally, in particular subcutaneously. A group of preferred pharmaceutical compositions of the invention are therefore those adapted for parenteral injection. The diluents and carriers used are therefore preferably those that adapt the active ingredient for parenteral administration. Examples of such diluents and carriers are solvents and suspending diluents such as water and water-miscible organic solvents, in particular sesame oil, groundnut oil, aqueous propylene glycol, and N,N'-

dimethyl formamide. Examples of pharmaceutical compositions of the invention are sterile isotonic saline aqueous solutions of the active ingredient, which may be buffered with a pharmaceutically acceptable buffer and are preferably pyrogen-free.

The pharmaceutical compositions of the invention generally contain 0.5 to wt. of a new aminophenylamidine or -cycloamidine of the invention or a non-toxic salt thereof.

The present invention also provides medicaments in dosage unit form as hereinafter defined comprising as an active ingredient at least one aminophenylamidine or -cycloamidine of general formula 1 given above or a non-toxic salt thereof, either alone or in admixture with a pharmaceutically acceptable solid or liquid diluent or carrier. In this case the diluent or carrier is preferably as defined above but can also be water or another common solvent.

The expression medicament in dosage unit form as used in the present specification means a medicament in the form of discrete portions each containing a unit dose or a multiple or sub-multiple of a unit dose of the active ingredient(s); for example, one, two, three of four unit doses or a half, a third or a quarter of a unit dose. A unit close is the amount of the active ingredient(s) to be administered on one occasion and will usually be a daily dose, or for example a half, a third, or a quarter of a daily dose depending on whether the medicament is to be administered once or, for example, twice, three times, or four times a day.

The discrete portions constituting the medicament in dosage unit form can include a protective envelope. The active ingredient can be undiluted and contained in such an envelope, or can be mixed with a pharmaceutically acceptable solid or liquid diluent or carrier as defined above. Such portions can for example be in monolithic coherent form, such as tablets, lozenges, pills, suppositories, or dragees; in wrapped or concealed form, the active ingredients being within a protective envelope, such as wrapped powders, cachets, sachets, capsules, or ampoules; or in the form of a sterile solution suitable for parenteral injection, such as ampoules of buffered, isotonic, sterile, pyrogen-free aqueous solution; or in any other form known in the art.

As stated above, it is preferred to administer the new aminophenylamidines and cycloamidines of general formula 1 or their salts perorally. Preferred medicaments in dosage unit form according to the invention are therefore those adapted for oral administration, such as tablets, pills, dragees, capsules, and cachets, as well as wrapped powders containing the active ingredient in powdered form with a powdered diluent or carrier for suspension in water before being taken.

As stated above it is also possible to administer the new aminophenylamidines and -cycloamidines parenterally. A further group of medicaments in dosage unit form according to the invention are therefore those adapted for parenteral injection, such as ampoules containing a measured quantity of a sterile isotonic saline injectable aqueous solution of the new active ingredient, which may be buffered with a pharmaceutically acceptable buffer and are preferably free of pyrogens.

The preferred unit dose for administration of the medicaments of the invention is 50 2,250 mg. of active ingredients. This will normally be administered once daily.

The invention further provides a method of combat- 20 ing parasitic infestation in an animal which comprises administering to the animal (preferably parenterally or perorally) an aminophenylamidine or -cycloamidine or a non-toxic salt thereof, a pharmaceutical composition or a medicament in dosage unit form according to the invention.

The administration is preferably carried out orally, but may also be carried out parenterally, in particular subcutaneously.

What we claim is:

l. A compound of the formula:

wherein R is hydrogen, alkyl of l to 5 carbon atoms, alkoxy alkyl of 2 to 5 carbon atoms or alkenyl of 2 to 5 carbon atoms;

each of R and R, independently of the other, is alkyl of l to 6 carbon atoms, or one is hydrogen and the other is alkyl of l to 6 carbon atoms;

R is alkyl of l to 5 carbon atoms;

R is alkyl of l to 4 carbon atoms, alkenyl of 2 to 4 carbon atoms, alkynyl of 2 to 4 carbon atoms, or cycloalkyl of 3 to 6 carbon atoms; and

R is hydrogen, alkyl of l to 5 carbon atoms or alkenyl of 2 to 5 carbon atoms;

or a salt thereof of a pharmaceutically acceptable acid.

2.. A compound according to claim 1 wherein R is alkyl.

3. A compound according to claim 1 wherein R is hydrogen or alkly or 1 to 3 carbon atoms;

R is methyl;

R is alkyl of l to 3 carbon atoms or one of R and R is hydrogen and the other is as above defined;

R is methyl or ethyl;

R is alkyl of l to 3 carbon atoms; and

R is methyl or ethyl.

4. A salt of a compound of claim 1 wherein said salt is selected from the group consisting of hydrohalides, sulphates, phosphates, nitrates, acetates, naphthalene disulphonates and pamoates. 

1. A COMPOUND OF THE FORMULA:
 2. A compound according to claim 1 wherein R5 is alkyl.
 3. A compound according to claim 1 wherein R1 is hydrogen or alkly or 1 to 3 carbon atoms; R3 is methyl; R4 is alkyl of 1 to 3 carbon atoms or one of R3 and R4 is hydrogen and the other is as above defined; R is methyl or ethyl; R5 is alkyl of 1 to 3 carbon atoms; and R6 is methyl or ethyl.
 4. A salt of a compound of claim 1 wherein said salt is selected from the group consisting of hydrohalides, sulphates, phosphates, nitrates, acetates, naphthalene disulphonates and pamoates. 